What is External Penetration Testing? A Comprehensive Guide

In the rapidly evolving world of technology, enterprises are becoming more susceptible to cyberattacks. External penetration testing is therefore an essential part of a thorough cybersecurity plan. It offers a proactive method of locating weak points and possible points of attack before malevolent actors may take advantage of them. The overview, basic guidance, tools, checklists, and best practices of external penetration testing will all be covered in this piece of content. So let’s get started right away!

External Penetration Testing: What Is It?

The method of external penetration testing in cyber security replicates actual attacks that come from sources other than the networks and systems of your company. It includes a thorough source code review and manual inspections and is carried out by an external security team that is not subject to the prejudices that an internal team might have. Depending on the extent of testing and your security requirements, it is frequently carried out on targets including web and mobile apps, cloud infrastructures, networks, and IoT devices at different depths.

Penetration testing: internal versus external

1. Unit: While external penetration testing is carried out by a separate group of security researchers, internal penetration testing is carried out by in-house security specialists.
2. Pricing: Keeping a full-time security staff on staff might be expensive. On the other hand, keeping a full-time security staff can be expensive.
3. Point of view: Internal security researchers frequently find it difficult to view a system from a hacker’s point of view because they are familiar with its specifics, yet external pen testing is excellent at simulating a hacker’s actions on the target system and provides a new viewpoint on the security of the system.
4. Regularity: Internal penetration testing can be carried out more regularly and with less preparation. However, conducting it typically takes time because it’s an external engagement. For an estimate of the cost of penetration testing, see this blog.
5. Compliance: Internal penetration testing does not meet the compliance criteria. To ensure compliance, however, external penetration testing is required.

External Pen Testing’s Significance in Cybersecurity

The External pen testing has a strong commercial justification for several reasons:

1. Safeguards sensitive data: External pentesting assists in locating weaknesses that can result in data breaches, protecting private client and company data.
2. Enforcement: To guarantee conformity to security standards, regulations like PCI-DSS and GDPR frequently require routine penetration testing.
3. Minimizes Danger: Organizations can lessen the possibility and effect of successful cyberattacks by proactively identifying and fixing flaws.
4. Maintains Company Status: A major data leak can harm a business’s standing. That risk is reduced with the use of external penetration testing.

External Penetration Testing Method

A comprehensive strategy comprising several procedures at each level is part of the external network penetration testing methodology.

1. Organizing and assessing: Specify your goals: Specified goals developed in partnership with the client (for example, identifying major gaps, assessing compliance, and so on).
2. The identification of the target system: a detailed list of all the IP addresses, domain names, web apps, and other resources that fall inside the parameters of the test.
3. Guidelines for Participation: Specify permitted attack methods as well as any systems or activities that are prohibited.
4. Observation: DNS lookups, search engine queries, social media, and business websites are examples of passive information gathering.
5. Active Information Gathering: Operating systems and active services are found using port scans and probes.
6. Examining vulnerabilities using automated tools: These tools perform scans to identify several known vulnerabilities.
7. Setting priorities: Pay attention to vulnerabilities that have a high chance of being exploited.
8. Exploitation and Chaining Vulnerabilities: Combining several flaws to make a bigger effect.
9. Data Exfiltration: Simulating attacker behavior to assess sensitive data exposure.
10. Lateral Movement: Searching the network for more assets and access points.
11. Establishing Backdoors: Creating mechanisms for long-term, covert access.
12. Pivoting: Using a compromised system to facilitate attacks targeting other networks.
13. Evidence: Thorough logs of actions, conclusions, and supporting data acquired.
14. Clear wording: Anyone with basic knowledge can understand the presentation of technical information.
15. Risk Setting Priorities: Emphasizing the weaknesses that present the biggest danger

External Penetration Testing Tools

External penetration testing does not use a single set of tools. Potential vulnerabilities are found using a few baseline tools. Nevertheless, more sophisticated inspections are carried out using operating systems, service-specific tests, or External Penetration Testing Tools and utilities based on standards. Among these tools are:

• Nmap
• Nikto
• Metasploit
• Burp Suite
• OWASP ZAP

External Penetration Testing Checklist

Here are eight important points typically included in the external pen testing checklist:

1. Pre-Engagement Preparation:

• Scope: Define web apps, external-facing servers (email, VPN connections, etc.), public IP ranges, domains, subdomains, and cloud assets (if any).
• Guidelines for Engagement: Make clear the off-limits strategies, scheduling constraints that are critical to business operations, communication routes for escalation, and allowed actions (including port scanning and denial of service testing).
• Obtain: Assess the tester’s need for a VPN or specialized testing environment and the external “source” IP addresses that will be used (to prevent firewall blocking).

2. Reconnaissance and Information Gathering:

• DNS Enumeration: Mapping domains and subdomains, locating mail servers (MX records), and locating possible points of entry.
• Whois Lookups: Compile the registrant’s details, possible contact details, and occasionally missed network blockages linked to the organization.
• Open Source Intelligence (OSINT): Search for exposed data, leaked credentials, employee details on social media, technological stacks referenced in job advertisements, etc.
• Shodan/Censys Searches: Find devices, services, and potential vulnerabilities that are accessible via the internet.

3. Identification of Potential Vulnerabilities in Infrastructure:

• Web servers, firewalls, VPN gateways, and mail servers that are outdated.
• Open ports and incorrectly set up services (defective protocols, superfluous services, and default settings).
• Software flaws that are known to exist (check against CVE databases).

4. Web Application Vulnerabilities:

• OWASP Top 10 (injection, XSS, broken authentication, etc.)
• Problems with business logic
• Incorrectly configured web server configuration

5. Cloud Risks (if applicable):

• Buckets of exposed storage (S3, etc.)
• Poor access control and permissions (IAM)
• Problems with cloud-based service configuration

6. Prioritize Vulnerabilities for Exploiting:

• Risk of Compromise: Pay close attention to those that present the greatest risk of unauthorized access or data exfiltration.
• Infrastructure Exploitation: Use well-known exploits, weak passwords, and configuration flaws to target network devices and servers that are visible to the outside world.
• Web Application Exploitation: Try to obtain sensitive information or unauthorized access using web application exploits (SQL injection, XSS, etc.).
• Social Engineering (if applicable): Techniques like phishing, pretexting, or other methods used to gain credentials or network access by interacting with personnel who engage with the public.

7. Technical Report:

• Vulnerabilities: Describe vulnerabilities, attack impact, evidence, exploit pathways, the Computer Vision and Security scores, and remediation recommendations in order of priority.

• Executive Overview: Management should receive a clear explanation of the risks, possible effects on the business, and high-level suggestions.

8. Afterwards, Remediation Support:

• Collaborate with IT departments to fix security flaws, fortify external defenses, and protect web applications. Ensure that the stakeholders are aware of the priorities for repair and triage.
• Knowledge Acquired: Examine the test to enhance the external pentesting procedure and adjust to new methods.

How Much Does External Penetration Testing Cost?

An external penetration test cost varies depending on how many assets need to be evaluated; for a small to medium-sized business, the cost can range from £2500 to £5,000. Customized pricing for a large organization is determined by a number of parameters, including frequency, assets, and associated scope factors.
The complexity and extent of the engagement have a significant impact on the estimated work and expense of an external penetration test. Here’s a closer look at the variables affecting the total time:

• A longer testing period is naturally required for more IP addresses, web applications, and other target systems.
• A thorough evaluation that includes both the deep exploitation and post-exploitation stages will take longer than a simple vulnerability scan.
• Experienced penetration testers may be able to work more quickly because of their refined abilities and expertise.

Vulnerability scanning and external pen testing: What’s the difference?

The following are the main distinctions between an external pen test and a vulnerability scan:

• In terms of depth, a vulnerability scan finds possible weaknesses that a penetration test aims to exploit in order to show the breadth of the attack lifecycle.
• In terms of scope, penetration is more concentrated on high-risk areas because of a concentrated strategy, while vulnerability scans are more expansive because they target several targets.
• In terms of time, a vulnerability scan takes less time, but a pentest takes more time because it requires more manual labor.
• The cost of a vulnerability scan is far lower than that of a pen test.
• A vulnerability scan can be utilized continually because it provides high-level checks across numerous hosts in a shorter amount of time. A penetration test simulates a real attack.

Selecting the Best External Penetration Testing companies

Choosing a credible External Penetration Testing company will revolutionize an organization’s experience. It will offer a comprehensive and hassle-free resolution. leveraging an easy-to-use platform for collaboration, leadership, and present-time vulnerability reporting.

Picking a reliable penetration testing company is important for optimizing the benefits of an external pentest. The following are some important points to consider:

• Expertise: Look for a provider with a strong background in external network and application testing. Inquire about the kinds of tests they have previously conducted.
• Credentials: Top industry certifications such as CEH, OSCP, GPEN, and GWAPT confirm current Technical skills. Find out what credentials their testers have.
• Status: To assess the caliber of deliveries, look through reviews and get referrals from previous customers. A trustworthy supplier needs to offer previews and be open and honest.
• Documentation: Verify that the supplier provides thorough, actionable reporting that includes risk ratings, proof-of-concept examples, and explicit corrective instructions.
• Contact: Before, during, and after the test, choose a provider who prioritizes communication with stakeholders.

Beginner’s Guide to External Penetration Testing Tutorial

There are five steps in the pen testing procedure.

1. Making Plans and Conducting Inspections:

• The first step entails defining the objectives and scope of a test, as well as the systems to be tested and the testing techniques to be employed.
• Obtaining information (such as mail servers, network, and domain names) to gain a better understanding of a target’s operations and its weaknesses.

2. Scanning:

• Knowing how the target application will react to different intrusion attempts is the next step. Usually, this is accomplished with:
  • Static Analysis: Examining an application’s code to gauge how it operates. This is done in a single pass, allowing technologies to scan the entire code.
  • Dynamic Analysis: Examining an application’s code while it is running. This scanning method provides a real-time perspective of an application’s performance, making it more useful.

3. Analysis:

• The results of the penetration test are then compiled into a report detailing:
  • Specific vulnerabilities that were exploited
  • Sensitive data that was accessed
  • The amount of time the pen tester was able to remain in the system undetected

4. Acquiring Entry:

• Web application attacks like SQL injection, backdoors, and cross-site scripting are used at this step to find weaknesses in a target.
• Testers attempt to exploit these vulnerabilities to determine the potential damage, usually by escalating privileges, stealing data, intercepting traffic, etc.

5. Preserving Data:

• This stage’s objective is to determine whether the vulnerability can be leveraged to establish a sustained presence in the compromised system—long enough for a malicious actor to obtain comprehensive access.
• The goal is to steal the most sensitive information from an organization by imitating advanced persistent threats, which can stay in a system for months.

The Best External Penetration Testing Practices

The first step in following general penetration testing best practices is to precisely define your objectives and scope. Next, establish your budget for The Best External Penetration Testing Practices, as expenses differ according to the complexity and type of test. Selecting the appropriate tools, processes, and vendor are further best practices.
All forms of pen testing should adhere to the following recommended practices:

1. Establish the parameters:

By specifying particular test objectives and criteria, defining the scope creates distinct boundaries. It provides solutions to important concerns like: Do we want to guarantee compliance or improve security? Which environment is the target? Which networks, assets, and systems require testing?

2. Know what the goals are:

Knowing the goals helps to focus the testing, which saves time and improves client happiness. Herring recently conducted a physical penetration test, for instance, in which the client imposed specific restrictions: no attempts to enter offices, no testing of clean desk regulations, and no wifi testing. Their only goal was to break through a certain door and reach the equipment beyond. The testing procedure was expedited by this targeted strategy, which was in perfect harmony with the client’s requirements.

3. Set a budget:

Penetration testing can range widely in price. The type of testing, duration, and coverage focus are all influenced by the budget. Take your goals, needs, and asset value into account while creating a budget.

4. Observe the law and obtain permission:

Always get permission from stakeholders and system owners before performing penetration testing to make sure that all legal requirements are met. Legal ramifications may result from testing systems without the appropriate ownership or authorization. Protecting private information from illegal access or exposure while testing is also crucial.

5. Use an approach:

Select approaches according to the assets, industry, and particular security needs and credentials of the company. Take into account how the methodology fits the goals and modify the strategy to handle the environmental risks and weaknesses.

6. Make use of scanning tools:

Time and resources are saved by using automatic scanning techniques.

7. Select a certified tester:

Choosing a penetration tester depends on establishing a strong rapport and trust. Ferrell suggests that new businesses assess the tester’s experience and area of expertise, such as government or healthcare. Their skills ought to be in line with the field and the level of sensitivity of the data being tested.

8. Set up the testing environment:

Set up the environment, secure any required permissions, and designate team members to examine the test report and address any problems found. If a high-risk vulnerability is found, be ready to take immediate action. Before beginning the pen test, set up monitoring systems so you can respond as needed. Informing all parties involved about the penetration testing operations will help to maintain transparency.

9. Address any weaknesses:

Examine the post-testing findings and handle vulnerabilities found during the test by adhering to the appropriate incident response guidelines and recommendations. To stop it from happening again, contain the problem, get rid of the threat, and move on from the incident.

10. Arrange and carry out remedial:

Determine each vulnerability’s underlying cause and create remedial plans. It is highly recommended by Tant and Herring to address vulnerabilities as soon as possible. These vulnerabilities remain until the following yearly pen test if they are not patched in 7-8 months.

Conclusion

External penetration testing is essential for businesses to identify and address vulnerabilities in their external infrastructure. It helps to improve their overall cybersecurity posture. Organizations can improve their defense against external attacks and protect key assets and data by simulating real-world cyber dangers. External network penetration testing allows businesses to stay one step ahead of cyber threats and effectively manage potential risks by conducting thorough observation, employing systematic testing techniques, and reporting frequently.

FAQ

Q. Where to start for your external network penetration test?

Ans: External network penetration testing usually starts with an interaction between the company and the penetration testing provider to determine the test’s objectives and boundaries. The organization will next utilize this information to develop a test strategy.

Q. How do you perform external penetration testing?

Ans: External penetration testing is the technique of assessing a network’s security from a different angle. This generally happens without gaining access to a company’s network or systems, imitating how a real-world attacker might try to breach protections.

Q. How Long Does External Network Penetration Testing Take?

Ans: The real test normally lasts one to two weeks, according to the dimension of the setting. It is rather unusual for a test to go more than two weeks, and when an environment is huge, a bigger pen test team should be appointed to confine the test window to one to two weeks.